Multistage ultra high radio frequency amplifier



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F. W. DUNMORE ET AL MULTISTAGE ULTRAHIGH RADIO FREQUENCY AMPLIFIER FiledDec. 27, 1935 3 Sheets-Sheet l PT M DUNMO/PE A. 1.. HUQNEfi HTTOIP/Vfyjam 5, 1193?. F. W. DUNMORE ET AL m a MULTISTAGE ULTRA HIGH RADIOFREQUENCY AMPLIFIER Filed Dec. 27, 1935 5 Sheets-Sheet 2 hm, 137 DUNMOREET AL 2,@@,@74

MULTISTAGE ULTRA HIGH RADIO FREQUENCY AMPLIFIER Filed Dec. 27, 1935 5Sheets-Sheet 5 W m ws'n'roms 1-? W nwwwomf 1.; 1.. HuQ fi' FTTO/PNE'VPatented it... 5, 1 937 UN ES PATENT OFFICE" MULTISTAGE ULTRA HIGH RADIOFREQUENCY AMLIFIER tary of Commerce Application December 27, 1935,Serial No. 56,350 9 Claims. (Cl. l'l9--1"l1) (Granted under the act ofMarch 3, 1883, as

amended April 30, 1928; 370 0. G. 757) This invention relates to anarrangement of concentriclines of multistage ultra high radio frequencyamplifiers.

The invention described herein, if patented, may be manufactured andused by orfor the Government for governmental purposes without thepayment to us of any royalty thereon.

The structure about to be described is designed as a practical physicalembodiment of the electrical features disclosed and illustrated in theapplication of Francis W. Dunmore, filed December 27, 1935, Serial No.56,349.

It is recognized as of great importance that the wiring to various tubeelements in ultra high radio frequency circuits be reduced to a minimum.length, and the object of this invention primarily is to accomplishthis, which we do by arranging the axes of the concentric lines inparallel planes about a common center, or in as close proximity to acommon center as is substantially feasible, the arrangement alsoreducing the over-all dimensions of the amplifier to a minimum.

It is to be understood that these drawings are for the purpose ofillustration only and are not designed for a definition of the limits ofour invention.

In the drawings- Figure 1 is a perspective view of an ultra high radiofrequency amplifier constructed in accordance with our invention, theconcentric trans mission lines being arranged in a circle about a commoncenter.

Figure 2 is a similar view of the lower portion or frame of theamplifier, or that portion that contains the electron tubes, shieldingpartitions, etc., when disposed in accordance with the arrangement shownin Figure 1.

Figure 3 is a bottom view which is more or less diagrammatic showing theconcentric lines in rectangular arrangement.

Figure 4 is a view showing the same arrangement of lines as in Figure 3,there being shown a supporting plate for the outer ends of theconcentric lines.

Figure 5 is a vertical section of a portion of one of the concentriclines, intended to show the manner of operating the tuning plunger inthe line.

Referring to Figure 1 of the drawings, wherein there is shown a 4-stageamplifier, numerals I, 2, 3, 4, and 5 designate, respectively, theconcentric line tuning impedances arranged about a common center, thecentral point in the arrangement being occupied by a central shieldingtube or cylinder 6 for the reception of a voltage divider or power pack.The concentric lines l-5 and the power pack tube 6 aresupported at theirlower ends in circular openings 1 in a frame 8 which will be describedin a little more detail later on, the frame being surrounded by ashielding cover 9, there being provided a suitable bottom platelil,having legs i l to raise the amplifier the desired distance aboveits support. These lines l-S and tube 6 are supported at their upperends in openings l2 in a disk I3, the lines being fitted with similarcaps l4 and the power pack with a cap l5. Each of the caps of theconcentric lines is provided with two diametrically opposite holes l8for the passage of con- .trol rods ll of insulating material, which rodsare secured at their lower ends to a tuning plunger l8 best shown inFigure 5, and by means of which rods, as will appear, the plunger ismoved with relation to the elements that are included in each concentricline or line assembly. We have mentioned the outer element of theconcentric line and this is the outer tube of each line such as l-5. Theother concentric line element designated by the numeral I9 is a tubearound which the plunger l8 fits, and upon which it slides for thepurpose of varying the electrical length of the concentric line whenmoved by the control rods, as intimated.

Above the disk I3 is another disk with holes 2! therein for the passageof the control rods, and the ends of each pair of rods are connected bya cross piece 22 so that each pair will be moved in unison.

Around the periphery of the upper disk are provided radially threadedapertures extending from the periphery of the disk to the holes for theouter rod of each pair of rods, and set-screws 23 are in the aperturesand arranged for engagement with a rod of each set by which, it isobvious, the rods may be fastened temporarily the disk E3 in anyadjusted tuning position so that when the disk as a whole is raised orlowered, all the control rods, and consequently all the plungers, aremoved accordingly in all of the concentric line tubes l-5, there being aknob 24 centrally located in the upper disk whereby after all tuningadjustments of the individual concentric lines are satisfactorily made,all of the control rods may be moved when the disk is moved. a

The tube or cylinder of the concentric line I is slotted, as indicatedat 25, for the passage and movement of one of the input terminals 26which is carried by an additional rod 21 of insulating material whichextends through an opening in the top of line I, and through the plungerin said line, the arrangement being for antenna adjustments, the otherinput terminal being indicated by the numeral 28, Figure 1, the outputterminals of the amplifier in the same figure, being designated by thenumerals 29 and 30.

Since the invention here resides in the main in the novel arrangement ofthe concentric lines, used in ultra high radio frequency amplifiers,using quarter wave concentric line impedance couplings between thestages, with the wiring to the ultra high frequency parts of the circuitreduced to minimum length, it is not necessary to describe the variouscircuits and elements that go to make up such amplifiers.

Figure 2 is provided to give a general idea of the construction of thebase of the amplifier that adapts it to receive the ends of theconcentric line tubes, the power pack cylinder or tube, and the electronor vacuum tubes a, b, c, d, and e, and to give a clearer understandingof the modifications and arrangement of the lines as shown in Figures 3and 4. The numeral 3| designates a plurality of shielding partitionsradially arranged around the central well 32, and extending to theperiphery of the frame 8. Each partition, with the exception of the onedesignated 33, has an opening 34 therein and other arrangements for thepassage and support of the electron tubes tb-e, which in the assembledamplifier, are appropriately connected with the elements constitutingthe concentric lines, the shielding partition 33 serving with anadjoining partition 3| to form an extra shielding compartment for thedetector output apparatus.

In Figures 3 and 4 what would correspond to the base in Figure l isdesignated by the numeral 35. This is a rectangular frame provided withinterior shielding partitions 39, which, together with the top 40, ends4|, sides 42 and bottom 43, form shielding compartments 44, 45, 46, 41,and 41 for amplifier elements that coact with the concentric lines I 5and other essentials of the amplifier assembly. The compartment 48 atthe corner of Figure 3 may be utilized for the elements of the outputcircuit of detector tube a, and the vacant space 48 in Figure 4 may beso used for the voltage divider or power pack.

In the arrangement shown in Figure 4, there is provided a supportingplate 49 for the outer ends of the lines, the plate itselfv beingsupported at any suitable distance from the shielding compartments, by anumber of rods 50.

By referring to the more or less diagrammatic view, Figure 3, it will beseen that the manner of connecting the electron tubes 11, b, c, d, and eis suggested, there being centrally arranged in each of the outerconcentric line tubes l-5 the inner concentric line tubes l9, Figure 5,upon which the plungers slide. The plates of the electron tubes areconnected to the D. C. voltage wire by means of an insulated wire 5|that passes through the tube; whereas the lead or wire 52 to the controlgrid of the electron tubes are connected directly to the central line.

We claim:

1. A multistage ultra high radio frequency amplifier using plunger typetuned concentric transmission lines as coupling impedances betweenstages, with the longest axis of each line parallel to the longest axisof the other lines and equidistant from a common center, whereby thewiring to the various tube elements is reduced to a minimum.

2. A multistage ultra high radio frequency amplifier with plunger typetuned concentric transmission lines as coupling impedances betweenstages, with the longest axis of each line parallel to the longest axisof the other lines and arranged about a common center, whereby thewiring to the various tube elements is reduced to a minimum.

3. A multistage ultra high radio frequency amplifier with plunger typetuned concentric transmission lines as coupling impedances betweenstages, with the longest axis of each line parallel to the longest axisof the other lines, whereby the wiring to the various tube elements isreduced to a minimum.

4. A multistage ultra high radio frequency amplifier with variablelength concentric transmission lines as coupling impedances betweenstages, with the longest axis of each line parallel to the longest axisof the other lines and equidistant from a common center about which isdisposed a shielding compartment containing the wiring to the variouselectron tube elements whereby the wiring to the said elements isreduced to a minimum.

5. A multistage ultra high radio frequency amplifier with plunger typetuned variable length concentric transmission lines as couplingimpedances between stages with the longest axis of each line parallel tothe longest axis of the other lines, whereby the wiring to the varioustube elements is reduced to a minimum.

6. A multistage ultra high radio frequency amplifier with plunger typetuned concentric transmission lines as coupling impedances betweenstages, with the longest axis of each line parallel to the longest axisof the other lines and equidistant from a common center, and with oneend of each line terminating in a separate shielding compartment,whereby the wiring to the various tube elements is reduced to a minimum.

7. A multistage ultra high radio frequency amplifier with plunger typetuned concentric transmission lines as coupling impedances betweenstages with the longest axis of each line parallel to the longest axisof the other lines and with one end of each line terminating in aseparate shielding compartment, whereby the wiring to the various tubeelements is reduced to a minimum.

8. In a multistage ultra high radio frequency amplifier with each stagehaving an input and output circuit, the combination of concentrictransmission lines as interstage coupling impedances consisting in eachinterstage of a concentric transmission line comprising an outergrounded tube and an inner concentric tube with the longest axis of eachinner tube parallel to the longest axes of the other inner tubes andequidistant from a common center, plunger type tuning means associatedwith each inner tube and. movable along its length, additional meansassociated with each inner tube for supplying the input and outputcircuits of each of said amplifier stages with the proper direct currentvoltages, whereby the wiring to each of said input and output circuitsis reduced to a minimum.

9. In a multistage ultra high radio frequency amplifier with each stagehaving an input and output circuit, the combination of concentrictransmission lines as interstage coupling impedances consisting in eachinterstage of a concentric transmission line comprising an outergrounded tube and an inner concentric tube each of said amplifier stageswith theproper diwith the longest axis of each inner tube paralrectcurrent voltages, whereby the wiring to lei to the longest axes of theother inner tubes, each of said input and output circuits is reducedplunger type tuning means associated with each to a minimum.

inner tube and movable along its length, addi- FRANCIS W. DUNMORE. 5tional means associated with each inner tube LEO L. HUGHES.

i'or supplying the input and output circuits of

